This project is designed to uncover the mechanism of cyclopentane ring formation for two fungal metabolites, brefeldin A and cis-jasmonic acid. Since it is not obvious how the cyclopentane ring of these molecules is formed in vivo - no obvious precedent exists - the research may elucidate new biochemical pathways for ring formation. Ancillary interests are the conversion of brefeldin A into the prostanoid skeleton, since it is a closely related structure, and the development of model systems to help understand the chemistry of polyketide biosynthesis.